MEDICINE HAT, Alta. – A spokesman for a southern Alberta county says a dead rat turned up by a cat could be a pest from a large nest discovered last summer.

Alberta has been proud of its reputation as a rat-free province, but that status was put into doubt when an infestation was uncovered at the Medicine Hat landfill in August. An 80-metre-long nest was destroyed the following month and at least 100 Norway rats were killed by city staff.

The most recent sighting was by a Cypress County woman who reported that her feline found the rodent last week on property near the landfill.

Agricultural fieldman Jason Storch says pest inspectors were sent out to investigate the latest sighting, but didn’t find any other vermin.

“The only evidence of rats we had was the dead rat itself. Upon investigating, we didn’t find any other signs,” he said Monday.

Storch said some stragglers from last year are to be expected as temperatures warm up.

“There’s always the chance that one or two may have been missed, and … they’re going to be looking for a new place to go this spring,” he said. “And with the nice weather we’ve had, it only make sense that they would be moving.”

Officials are asking residents who think they have seen a rat to call the county office or Medicine Hat’s bylaw department.

“It’s important for all of us to remember that there will be stragglers from last year’s infestation,” Storch said. “We want everybody to stay vigilant. We want everybody to keep their eyes open.

“We’re going to stick at it and make sure this gets dealt with.”

Fieldmen, known by Albertans as the “rat patrol,” have worked for years targeting invading rats within a control zone along the province’s eastern boundary.

Until last summer, Alberta had only had isolated cases since the 1950s. Pet rats are forbidden under provincial law and rat sightings are treated with the utmost urgency.

The province estimates its rat control measures have prevented what would have been $1 billion in rodent-caused damage over the last 50 years.